总线型光接入网的公平性分析

On the fairness issues in optical access networks

为了减少光接入网异步传输模型中的接入延时,根据一种实用的总线型光接入拓扑网络结构,对此模型下的媒质接入协议进行分析研究。通过对网络中各节点接入时延算法的理论仿真,验证此种双总线型接入模型及相应接入协议能较准确地反应系统接入延时,并根据用户的优先级别给出接入时延的范围,从而提出通过改变上下游用户的优先级,实现用户的动态带宽分配,来减少用户的接入延时,为解决系统的公平性问题给出参考协议模型。

In order to reduce the access delay of an asynchronous transmission model in optical access networks,its MAC（Medium Access Control） protocol is analyzed based on a practical bus-based optical access networks.A simulation shows that,the access model of the double bus-based can truly describe the access delay,and the bound of the access delay can be determined based on PRI（Preemptive Repeat Identical） of users.Thus,it＇s possible to reduce the access delay by changing priority of users and allocating bandwidth dynamically,and the fairness issues can be treated becomingly.